In the field of mobile communications, the provision of services is underway by Mobile Virtual Network Operators (MVNOs) that use existing communication facilities, such as base stations, which are under the control of Mobile Network Operators (MNOs) (see Japanese Laid-open Patent Publication No. 2007-318361). An MVNO contracts with a single MNO so as to communicate with a mobile device by using a cell formed by a base station that is under the control of the MNO and so as to provide unique services, such as content delivery, for mobile devices. To provide such services, the MVNO selects a cell with a desired radio quality (hereafter, referred to as an “optimum cell”) from a plurality of cells that are under the control of the MNO, with which the MVNO has made a contract, and performs communication with a mobile device via a base station that forms the optimum cell.
Because the customer needs are diversified and the number of MNOs has increased in recent years, it is assumed that in the future an MVNO will make contracts with a plurality of MNOs so as to provide services by using communication facilities that are under the control of the MNOs in combination.
In order for the MVNO to provide services by using the communication facilities that are under the control of a plurality of MNOs in combination, it is assumed that an optimum cell is selected from the cells that are formed by the respective base stations owned by the MNOs and communication is performed between the MVNO and a mobile device via the base station that forms the optimum cell.
A possible method for performing such communication is, for example, that the mobile device selects an optimum cell so as to perform communication with the MVNO via the base station of the MNO that forms the selected optimum cell, as illustrated in FIG. 10 (hereafter, referred to as a “mobile-device-driven method”).
As illustrated in FIG. 11, another possible method is that the MVNO selects an optimum cell and notifies the mobile device of the selected optimum cell so as to perform communication with the mobile device (hereafter, referred to as an “MVNO-driven method”). A detailed explanation is given here of the MVNO-driven method. First, the MVNO collects, from each MNO, radio quality information that indicates the radio quality, such as the presence or absence of access restrictions or the level of crossed lines, of each cell formed by a base station owned by each MNO (see FIG. 11 (1)). The MVNO selects an optimum cell by using the radio quality information (see FIG. 11 (2)) and then notifies each of the MNOs of the optimum cell information that indicates the selected optimum cell (see FIG. 11 (3)). After being notified by the MVNO, each MNO notifies a mobile device of the optimum cell information (see FIG. 11 (4)). Afterwards, the mobile device performs communication with the MVNO via the base station of the MNO that forms the optimum cell indicated by the optimum cell information (see FIG. 11 (5)).
Here, a comparison is made between the mobile-device-driven method and the MVNO-driven method. FIG. 12 is a diagram that illustrates the mobile-device-driven method, and FIG. 13 is a diagram that illustrates the MVNO-driven method. As illustrated in FIG. 12, in the mobile-device-driven method, a user of the mobile device needs to select the optimum cell and the MNO that controls the optimum cell, which causes the problem of a heavy burden being imposed on users. On the other hand, as illustrated in FIG. 13, in the MVNO-driven method, the user of the mobile device does not need to select the optimum cell and the MNO that controls the optimum cell; therefore, a low burden is imposed on users. Thus, it is considered that the MVNO-driven method has an advantage over the mobile-device-driven method when the MVNO provides services by using the communication facilities that are under the control of a plurality of MNOs in combination.
In the above-described MVNO-driven method, as a condition for the MVNO to select an optimum cell and the MNO that controls the optimum cell, the MVNO collects, from the MNO, radio quality information that indicates the radio quality, such as the presence or absence of access restrictions or the level of crossed lines, of each cell. Such radio quality information is closely related to confidential information, such as information on the location of base stations, which is not disclosed to other companies because of the contract that is based on the contract conditions between the MNOs. Therefore, there is a low possibility that the MVNO can actually collect substantial radio quality information from the MNO. Hence, the MVNO may incorrectly select an optimum cell and the MNO that controls the optimum cell. In such a case, the mobile device may not be able to use the base station that forms the optimum cell. As a result, the communication state between the mobile device and the MVNO deteriorates, which causes a problem in that the MVNO may not be able to provide satisfactory services.